// 导出页面为PDF格式  
import html2Canvas from 'html2canvas'
import JsPDF from 'jspdf'
export default {
	install(Vue, options) {
		Vue.prototype.getPdf = function (id) {
			var title = this.htmlTitle
			return new Promise((res, rej) => {
				try {
					html2Canvas(document.querySelector(id), {
						allowTaint: true
					}).then(function (canvas) {
						let contentWidth = canvas.width
						let contentHeight = canvas.height
						let pageHeight = contentWidth / 592.28 * 841.89
						let leftHeight = contentHeight
						let position = 0
						let imgWidth = 595.28
						let imgHeight = 592.28 / contentWidth * contentHeight
						let pageData = canvas.toDataURL('image/jpeg', 1.0)
						let PDF = new JsPDF('', 'pt', 'a4')
						if (leftHeight < pageHeight) {
							PDF.addImage(pageData, 'JPEG', 0, 0, imgWidth, imgHeight)
						} else {
							while (leftHeight > 0) {
								PDF.addImage(pageData, 'JPEG', 0, position, imgWidth, imgHeight)
								leftHeight -= pageHeight
								position -= 841.89
								if (leftHeight > 0) {
									PDF.addPage()
								}
							}
						}
						PDF.save(title + '.pdf')
						res()
					})
				} catch (error) {
					rej(error)
				}
			})

		}
	}
}
